We report on the creation and characterization of heteronuclear $^{40}\text{K}^{87}\text{R}\text{b}$ Feshbach molecules in an optical dipole trap. Starting from an ultracold gas mixture of $^{40}\text{K}$ and $^{87}\text{R}\text{b}$ atoms, we create as many as 25 000 molecules at 300 nK by rf association. Optimizing the association process, we achieve a conversion efficiency of 25%. We measure the temperature dependence of the rf association process and find good agreement with a phenomenological model that has previously been applied to Feshbach molecule creation by slow magnetic-field sweeps. We also present a measurement of the binding energy of the heteronuclear molecules in the vicinity of the Feshbach resonance and provide evidence for Feshbach molecules as deeply bound as 26 MHz.We report on the creation and characterization of heteronuclear $^{40}\text{K}^{87}\text{R}\text{b}$ Feshbach molecules in an optical dipole trap. Starting from an ultracold gas mixture of $^{40}\text{K}$ and $^{87}\text{R}\text{b}$ atoms, we create as many as 25 000 molecules at 300 nK by rf association. Optimizing the association process, we achieve a conversion efficiency of 25%. We measure the temperature dependence of the rf association process and find good agreement with a phenomenological model that has previously been applied to Feshbach molecule creation by slow magnetic-field sweeps. We also present a measurement of the binding energy of the heteronuclear molecules in the vicinity of the Feshbach resonance and provide evidence for Feshbach molecules as deeply bound as 26 MHz.

arXiv:0712.3889Physical Review AJul 23, 2008120 citations

Ultracold Feshbach Molecules

Rudolf Grimm, Francesca Ferlaino, Steven Knoop

CRC Press eBooksJun 25, 20092 citations

High phase-space density gas of NaCs Feshbach molecules

Aden Z. Lam, Niccolò Bigagli, Claire Warner +5 more

We report on the creation of ultracold gases of bosonic Feshbach molecules of NaCs.The molecules are associated from overlapping gases of Na and Cs using a Feshbach resonance at 864.12(5) G.We characterize the Feshbach resonance using bound-state spectroscopy, in conjunction with a coupled-channel calculation.By varying the temperature and atom numbers of the initial atomic mixtures, we demonstrate the association of NaCs gases over a wide dynamic range of molecule numbers and temperatures, reaching 70 nK for our coldest systems and a phase-space density near 0.1.This is an important stepping stone for the creation of degenerate gases of strongly dipolar NaCs molecules in their absolute ground state.We report on the creation of ultracold gases of bosonic Feshbach molecules of NaCs.The molecules are associated from overlapping gases of Na and Cs using a Feshbach resonance at 864.12(5) G.We characterize the Feshbach resonance using bound-state spectroscopy, in conjunction with a coupled-channel calculation.By varying the temperature and atom numbers of the initial atomic mixtures, we demonstrate the association of NaCs gases over a wide dynamic range of molecule numbers and temperatures, reaching 70 nK for our coldest systems and a phase-space density near 0.1.This is an important stepping stone for the creation of degenerate gases of strongly dipolar NaCs molecules in their absolute ground state.

arXiv:2202.03355Physical Review ResearchApr 25, 202224 citations

Observation of Heteronuclear Feshbach Molecules from a Rb85–Rb87 Gas

Scott B. Papp, Carl Wieman

We report on the observation of ultracold heteronuclear Feshbach molecules. Starting with a $^{87}\mathrm{Rb}$ Bose-Einstein condensate and a cold atomic gas of $^{85}\mathrm{Rb}$ , we utilize previously unobserved interspecies Feshbach resonances to create up to 25 000 molecules. Even though the $^{85}\mathrm{Rb}$ gas is nondegenerate, we observe a large molecular conversion efficiency due to the presence of a quantum degenerate $^{87}\mathrm{Rb}$ gas; this represents a key feature of our system. We compare the molecule creation at two different Feshbach resonances with different magnetic-field widths. The two Feshbach resonances are located at $265.44\ifmmode\pm\else\textpm\fi{}0.15\text{ }\mathrm{G}$ and $372.4\ifmmode\pm\else\textpm\fi{}1.3\text{ }\text{ }\mathrm{G}$. We also directly measure the small binding energy of the molecules through resonant magnetic-field association.We report on the observation of ultracold heteronuclear Feshbach molecules. Starting with a $^{87}\mathrm{Rb}$ Bose-Einstein condensate and a cold atomic gas of $^{85}\mathrm{Rb}$, we utilize previously unobserved interspecies Feshbach resonances to create up to 25 000 molecules. Even though the $^{85}\mathrm{Rb}$ gas is nondegenerate, we observe a large molecular conversion efficiency due to the presence of a quantum degenerate $^{87}\mathrm{Rb}$ gas; this represents a key feature of our system. We compare the molecule creation at two different Feshbach resonances with different magnetic-field widths. The two Feshbach resonances are located at $265.44\ifmmode\pm\else\textpm\fi{}0.15\text{ }\mathrm{G}$ and $372.4\ifmmode\pm\else\textpm\fi{}1.3\text{ }\text{ }\mathrm{G}$. We also directly measure the small binding energy of the molecules through resonant magnetic-field association.

arXiv:cond-mat/0607667Physical Review LettersOct 31, 2006163 citations

Polaritonic Feshbach resonance

Naotomo Takemura, Stéphane Trebaol, Michiel Wouters +2 more

arXiv:1408.1499Nature PhysicsJun 20, 2014146 citations

We report on the creation and characterization of heteronuclear

^{40}\text{K}^{87}\text{R}\text{b}

Feshbach molecules in an optical dipole trap. Starting from an ultracold gas mixture of

^{40}\text{K}

and

^{87}\text{R}\text{b}

atoms, we create as many as 25 000 molecules at 300 nK by rf association. Optimizing the association process, we achieve a conversion efficiency of 25%. We measure the temperature dependence of the rf association process and find good agreement with a phenomenological model that has previously been applied to Feshbach molecule creation by slow magnetic-field sweeps. We also present a measurement of the binding energy of the heteronuclear molecules in the vicinity of the Feshbach resonance and provide evidence for Feshbach molecules as deeply bound as 26 MHz.

We report on the observation of ultracold heteronuclear Feshbach molecules. Starting with a

^{87}\mathrm{Rb}

Bose-Einstein condensate and a cold atomic gas of

^{85}\mathrm{Rb}

, we utilize previously unobserved interspecies Feshbach resonances to create up to 25 000 molecules. Even though the

^{85}\mathrm{Rb}

gas is nondegenerate, we observe a large molecular conversion efficiency due to the presence of a quantum degenerate

^{87}\mathrm{Rb}

gas; this represents a key feature of our system. We compare the molecule creation at two different Feshbach resonances with different magnetic-field widths. The two Feshbach resonances are located at $265.44\ifmmode\pm\else\textpm\fi{}0.15\text{ }\mathrm{G}$ and $372.4\ifmmode\pm\else\textpm\fi{}1.3\text{ }\text{ }\mathrm{G}$. We also directly measure the small binding energy of the molecules through resonant magnetic-field association.